diff --git a/livesync/indico_livesync/simplify.py b/livesync/indico_livesync/simplify.py
index e04834a..9d90f59 100644
--- a/livesync/indico_livesync/simplify.py
+++ b/livesync/indico_livesync/simplify.py
@@ -82,8 +82,8 @@ def _process_cascaded(records):
 
     event_records = {rec.event_id for rec in records if rec.type == EntryType.event}
     session_records = {rec.session_id for rec in records if rec.type == EntryType.session}
-    contribution_records = {rec.contribution_id for rec in records if rec.type == EntryType.contribution}
-    subcontribution_records = {rec.subcontribution_id for rec in records if rec.type == EntryType.subcontribution}
+    contribution_records = {rec.contrib_id for rec in records if rec.type == EntryType.contribution}
+    subcontribution_records = {rec.subcontrib_id for rec in records if rec.type == EntryType.subcontribution}
 
     changed_events = set()
     changed_contributions = set()